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1.
Nathan  S. Senthil  Chung  Paul Gene  Murugan  K. 《Phytoparasitica》2004,32(5):433-443
The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.  相似文献   

2.
The toxicity and physiological (enzyme and nutritional indices) effect of Dysoxylum triterpenes 3β,24,25-trihydroxycycloartane and beddomei lactone were evaluated on the rice leaffolder Cnaphalocrocis medinalis (Guenée). The LC50 [6.66 ppm (SD = 0.31), 5.79 ppm (SD = 0.33) for 3β,24,25-DHCL and BL, respectively] and LC 90 [14.63 ppm (SD = 0.36), 13.49 ppm (SD = 0.27) for 3β,24,25-DHCL and BL, respectively] were identified by probit analysis. Fourth instars were exposed to various concentrations (1.5, 3, 6, and 12 ppm) of Dysoxylum triterpenes. Results showed that treated larvae exhibited reduced food consumption and enzyme activity. Food consumption, digestion, relative consumption rate, efficiency of conversion of ingested food, efficiency of conversion of digested food, and relative growth rate values declined significantly but the approximate digestibility of treated larvae was significantly higher as a result of treatment (in particular 6 and 12 ppm). Likewise, the gut enzymes acid phosphatases, alkaline phosphatases, and adenosine triphosphatases were significantly inhibited by the Dysoxylum triterpenes. The high biological activity of these triterpenes from Dysoxylum sp. could be used as an active principle during the preparation of botanical insecticides for insect pest like rice leaffolder.  相似文献   

3.
Laboratory assays were done to evaluate the effect of Melia azedarach L. (Rutales: Meliaceae) seed extract on nutritional indices and gut enzymes acid phosphatases, alkaline phosphatases, adenosinetriphosphatases, and lactate dehydrogenase of the rice leaffolder (RLF) Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae). Larvae were fed a treated rice-leaf diet containing the seed extract and their midgut was used for enzyme determination. Laboratory experiments showed that the seed extract suppressed the larval activity of C. medinalis even at a low dose. Gross dietary utilization (efficiency of conversion of ingested and digested food) of RLF decreased after ingesting the treated rice-leaf diet. Food consumption, digestion, relative consumption rate, efficiency of conversion of ingested food, efficiency of conversion of digested food, and relative growth rate values declined significantly. As compared to the control, consumption of the extract containing rice-leaf diet resulted in a 69% reduction of the acid phosphatases activity, a 71% reduction of the alkaline phosphatases activity, a 46% reduction of the adenosine triphosphatases activity, and a 52% inhibition of the lactate dehydrogenase activity.  相似文献   

4.
The effects of azadirachtin (AZA) and nucleopolyhedrovirus (NPV) on midgut enzyme activity in Spodoptera litura Fabricius (Lepidoptera: Noctuidae) (Tobacco cutworm) were evaluated. Gut enzyme activities were decreased by AZA and NPV individually and in combination. When S. litura larvae were fed a diet of castor leaves treated with AZA and NPV in bioassays, gut enzyme—acid phosphatases, alkaline phosphatases, adenosine triphosphatases, and lactate dehydrogenase—activities were decreased. There were statistically significant differences (P ? 0.05) in enzyme activities between combined and individual treatment. A synergistic effect of botanical insecticides and virus was found when combined in low doses. These effects are most pronounced in early instars. Maximum weight loss (59-72%) occurred, when AZA and NPV were combined.  相似文献   

5.
用高浓度CO2气体胁迫处理药材甲老熟幼虫及体外磷酸酯酶,通过终点法测定酶活性变化,分析气调胁迫与磷酸酯酶活性变化之间的关系。结果显示,高浓度CO2密闭处理药材甲老熟幼虫6 h和12 h,ACP比活力分别升高6.41%和18.96%,ALP活力分别降低了7.69%和7.91%。ACP经CO2体外处理30、60、120 min,比活力分别增强92.77%、127.43%和67.91%。可见,高浓度CO2气调胁迫处理对药材甲老熟幼虫ACP和ALP活力均有一定影响。  相似文献   

6.
In the present study toxic effects of active molluscicidal component of Areca catechu and Carica papaya was studied on certain enzymes in the nervous tissue of freshwater snail Lymnaea acuminata. In in vivo and in vitro exposure of arecoline (active component of Areca catechu seed) and papain (C. papaya latex and seed) significantly inhibited the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that arecoline and papain caused competitive and uncompetitive inhibition of AChE, respectively, whereas arecoline caused competitive-non-competitive inhibition of ACP/ALP and papain caused non-competitive inhibition of ACP/ALP. Thus the inhibition of AChE, ACP and ALP by arecoline and papain in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of A. catechu and C. papaya, respectively.  相似文献   

7.
Photo-oxidation of the neem limonoids nimbin and salannin with UV light in the presence of oxygen gives two isomeric lactone products per limonoid, nimbinolide and isonimbinolide, and salanninolide and isosalanninolide, respectively. When compared in insect tests with the important limonoids of neem seeds, azadirachtin, nimbin and salannin, isonimbinolide and isosalanninolide show activity greater than that of nimbin or salannin and in some respects show activity approaching that of azadirachtin. The photo-oxidation products were tested for anti-feedant activity and toxicity against larvae of three species of Lepidoptera, Spodoptera littoralis (Boisd), Spodoptera frugiperda (FE Smith) and Helicoverpa armigera (Hübner) and nymphs of the locusts Schistocerca gregaria (Forsk?l) and Locusta migratoria (L).  相似文献   

8.
The excessive use of pesticides in agriculture has sparkled the interest of scientists in investigating the harmful effects of these compounds. The present study evaluates the pesticides Atrazine and Roundup (glyphosate) on biochemical and molecular aspects of Biomphalaria alexandrina snails. The results showed that LC10 of these two pesticides caused considerable reduction in survival rates and egg production of treated snails. Additionally, Atrazine proved to be more toxic to B. alexandrina snails than Roundup. In treated snails, glucose concentration (GL) in the hemolymph as well as lactate (LT) and free amino acid (FAA) in soft tissues of treated snails increased while glycogen (GN), pyruvate (PV), total protein (TP), nucleic acids (DNA and RNA) levels in snail’s tissues decreased. The activities of glycogen phosphorylase (GP), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), succinic dehydrogenase (SDH), acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and phosphatases (ACP and ALP) enzymes in homogenate of snail’s tissues were reduced in response to the treatment with the two pesticides while lipid peroxide (LP) and transaminases (GOT and GPT) activity increased (P < 0.001). The changes in the number, position and intensity of DNA bands induced by pesticides may be attributed to the fact that pesticide can induce genotoxicity through DNA damage. It was concluded that the pollution of the aquatic environment by Atrazine and Roundup pesticides, would adversely affect the metabolism of the B. alexandrina snails, and have adverse effects on its reproduction.  相似文献   

9.
An enzyme that possesses the glutathione S-transferase (GST) activity was found in the rice leaffolder moth, Cnaphalocrocis medinalis. The enzyme was purified to homogeneity for the first time by ammonium sulfate fractionation and affinity chromatography. The resultant enzyme revealed a single band with a molecular mass of 24 kDa by SDS-polyacrylamide gel electrophoresis under reduced conditions. When assayed with 1-chloro-2,4-dinitrobenzene, a universal substrate for GST, the purified GST had an optimum pH at 8.0, and was fairly stable at pH 3-10 and at temperatures below 50 °C. The enzyme was also able to conjugate glutathione to 4-hydroxynonenal, a cytotoxic lipid peroxidation product. The present GST was inhibited by fenitrothion, permethrin, and deltamethrin, suggesting that the GST could be involved in metabolizing these organophosphorus and pyrethroid insecticides.  相似文献   

10.
梨小食心虫滞育过程中几种代谢酶活力的相关变化   总被引：2，自引：2，他引：0  
梨小食心虫Grapholita molesta是一种重要的蛀果害虫,以老熟幼虫滞育越冬。为明确梨小食心虫滞育幼虫对低温的生理适应性,用3,5-二硝基水杨酸比色法、双试剂法及代谢酶活力测试盒分别测定了梨小食心虫幼虫体内海藻糖酶（trehalase,TRE）、山梨醇脱氢酶（sorbitol dehydrogen-ase,SDH）及己糖激酶（hexokinase,HK）、丙酮酸激酶（pyruvate kinase,PK）和碱性磷酸酶（alkalinephosphatase,ALP）的活力变化。在低温条件下,滞育幼虫体内各酶活力明显不同,TRE活力在滞育初期显著提高,而后随滞育时间的延长而逐渐降低;SDH活力总体变化较为平缓,变化量较小;HK、PK和ALP活力在滞育前期均显著降低,且随后一直保持在较低水平。滞育期间,5种代谢酶的活力均与滞育发育及温度有关;通过相关代谢酶的调节,梨小食心虫的代谢速率维持在较低水平,提高了虫体的耐寒能力,从而顺利完成滞育。  相似文献   

11.

The effect of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders was studied in an irrigated rice area in the Philippines. Nitrogen was applied at three levels (0, 75 and 150 kg N ha-1), and its impact on crop growth and yield, arthropod abundance, and rates of leaffolder parasitism and survival was assessed with weekly samples. Rice plants were taller and had a higher leaf nitrogen content with increasing levels of nitrogenous fertilization, but grain yield was highest at the medium nitrogen level. Herbivores, predators, and parasitoids increased in abundance with nitrogenous-fertilization level. The average density of rice leaffolder larvae at the highest nitrogen level was eight times the density at zero nitrogen level, and the peak percentage injured leaves increased from 5 to 35%. The strong increase in larval density was due to the positive effect of nitrogenous-fertilization on egg recruitment and survival of medium-sized larvae. The percentage parasitism of eggs and larvae was not affected by nitrogenous-fertilization. The increase in survival of medium-sized larvae with nitrogen levels was associated with lower predator to leaffolder ratios. The strong effect of nitrogenous-fertilization in the present small-scale experiment was attributed mainly to allowing the moths an oviposition choice between plots with different application levels of nitrogen. Therefore it is hypothesized that the effect of increasing nitrogenous-fertilization level on leaffolder larval densities will be less pronounced when implemented over a large area.  相似文献   

12.
In search for new local plant molluscicides for the control of the vectors of schistosomiasis, we compared the molluscicidal action of the extract of Ginkgo biloba sarcotesta by benzinum (EGSB) to that of arecoline (ARE) and niclosamide (NIC) against Oncomelania hupensis snails. NIC showed the highest toxicity on snails with 24 h LC50 vales of 0.12 mg/L and LC90 of 0.98 mg/L, while the LC50 and LC90 of EGSB were much lower than that of ARE. Sublethal in vivo 24 h exposure to 40% and 80% LC50 of NIC, EGSB and ARE altered the activities of different enzymes in different body tissues of snails. EGSB could significantly inhibit Choline esterase (ChE), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP) and Malic dehydrogenase (MDH) activities both in the cephalopodium and liver. ARE could significantly cause a reduction in ChE, ALP activities in the cephalopodium and ChE, ALT, ALP, Succinodehydrogenase (SDH), MDH activities in the liver. NIC significantly altered activities of ChE, ALT, ALP, SDH, and MDH in the cephalopodium and ChE, ALT, ALP, SDH activities in the liver. All molluscicides could not affect Lactate dehydrogenase (LDH) activity in the cephalopodium and the liver. Maximum inhibition of ALT and MDH activities was found in the cephalopodium and liver of snails treated with 80% of 24 h LC50 of EGSB. However, NIC and ARE caused maximum reduction in ALP and SDH activities, respectively. The results indicated that molluscicidal action of EGSB was different to that of ARE and NIC in some extent.  相似文献   

13.
BACKGROUND: The biological control of plant pests and diseases using a single organism has been reported to give inconsistent and poor performance. To improve the efficacy, bioformulations were developed possessing mixtures of bioagents. RESULTS: Bioformulations combining Pseudomonas fluorescens Migula strains Pf1 and AH1 and Beauveria bassiana (Balsamo) Vuill. isolate B2 were developed and tested for their efficacy against leaffolder pest and sheath blight disease on rice under glasshouse and field conditions. The combination of Pf1, AH1 and B2 effectively reduced the incidence of leaffolder insect and sheath blight disease on rice compared with other treatments. An in vitro assay of leaffolder preference to rice leaf tissues treated with Pf1 + AH1 + B2 biformulation showed variation from normal growth and development of leaffolder larvae. Plants treated with the Pf1 + AH1 + B2 combination showed a greater accumulation of enzymes, lipoxygenase and chitinase activity against leaffolder insect compared with other treatments. Similarly, the plants showed a higher accumulation of defence enzymes, peroxidase and polyphenol oxidase activity against sheath blight pathogen in Pf1 + AH1 + B2 treatment compared with the untreated control. The bioformulation mixture attracted the natural enemy population of leaffolder under field conditions. In addition, a significant increase in rice grain yield was observed in Pf1 + AH1 + B2 treatment compared with the untreated control. CONCLUSION: The combination of P. fluorescens strains and B. bassiana isolate effectively reduced the incidence of leaffolder insect and sheath blight disease on rice plants and showed the possibility of controlling both pest and disease using a single bioformulation. Copyright © 2010 Society of Chemical Industry  相似文献   

14.
Insecticidal tests using diazinon showed that the mortality of Plutella xylostella larvae parasitized by Cotesia plutellae was reduced by 4.6-fold compared to that of the nonparasitized hosts. The use of chemicals with synergistic effect to insecticides in toxicity assay helps to elucidate the kind of enzyme involved in lowering insect mortality. Synergism of diethyl maleate and piperonyl butoxide with diazinon resulted to 2.4- and 1.9-fold increase, respectively, in susceptibility of parasitized larvae compared to those of nonparasitized larvae. These results indicated the possibility that the decrease in susceptibility to diazinon was due to the elevated activities of glutathione-S-transferase (GST) and cytochrome P450 monooxygenase (CYP), respectively. The GST activities in parasitized larvae were significantly higher than those of nonparasitized ones starting from three days post-parasitization until emergence of parasitoid larva. High GST activities during late parasitism could be attributed to both enzyme activities toward diazinon of parasitized P. xylostella larva itself and C. plutellae larva inside larval host. High GST activity one day after parasitization, although statistical significance was not detected, was caused by polydnavirus (PDV) and the venom of C. plutellae not by parasitoid larvae. Artificial injection of PDV plus venom demonstrated that the resulting increase in GST activity is similar to the increase brought by parasitization. High CYP activity after 3 days post-parasitization in parasitized larva was attributed mainly to the activity of parasitoid larva. Carboxylesterase activity in the parasitized host remained at a high level, while that in the nonparasitized host decreased slightly as pupation approaches. On the other hand, acetylcholinesterase activity also remained constant after parasitization until larval emergence, while that of the nonparasitized hosts decreased gradually as the host larvae approach pupation. These results were supported by inhibition tests using diazoxon in vitro.  相似文献   

15.
The racemic product of metolachlor contains two R-enantiomers and two S-enantiomers. S-Metolachlor is a more effective herbicidal agent than rac-metolachlor; currently, it is widely used instead of rac-metolachlor. The comparative toxicity of rac- and S-metolachlor was assessed on the basis of their effects on some enzyme activities of the fifth instar of the silkworm, Bombyx mori L. These results suggest that rac-metolachlor and S-metolachlor have different effects on enzyme activities of fifth-instar silkworm larvae. Hemolymph lactate dehydrogenase and catalase activity levels in silkworms treated with rac-metolachlor were much lower than those in silkworms treated with S-metolachlor. Control hemolymph ACP activity was 44-73% higher than that of rac-metolachlor-treated hemolymph, but the difference was not large between S-metolachlor treatment and the control. Midgut alkaline phosphatase activity of silkworms treated with rac-metolachlor was 46% lower than control activity, and the effect of S-metolachlor on midgut alkaline phosphatase activity was minor. The difference between the two herbicides was apparent mainly during the first 5 days of the fifth instar, and then gradually disappeared. It is shown that compared with S-metolachlor, rac-metolachlor is more toxic to economically important silkworms because of its effects on some enzymes and on metabolism.  相似文献   

16.
The compatibility and protectant potential of Calneem® oil derived from the neem tree Azadirachta indica and two parasitoids, Habrobracon hebetor and Venturia canescens, for the control of the rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) and the tropical warehouse moth Cadra cautella Walker (Lepidoptera: Pyralidae) in stored rice and wheat, were evaluated in the laboratory. Calneem® oil (= neem oil) is a biopesticide produced, registered and marketed in Ghana by AQUA AGRIC Community Projects (AACP/Caldor Ghana Ltd., Tema). It contains 0.3% azadirachtin as its major active ingredient. The oil was emulsified with water using 0.07% soap. Fourth instar moth larvae were held in grain treated with neem oil only, grain treated with one of the parasitoids only, grain treated with a combination of neem and one of the parasitoids, and a control with untreated grain. Neem oil was applied at concentrations from 5,000 to 30,000 ppm. All samples were kept in growth cabinets maintained at 25°C and 65–70% r.h. Adult emergence was recorded after 4 weeks. Parasitoid or neem treatments alone reduced the emergence of C. cephalonica and C. cautella. In general, parasitoid releases were as effective as a combination of neem oil and parasitoids. At the lowest dose, 5,000 ppm, the combination of neem and parasitoid was more effective than the neem alone. The number of adults of H. hebetor and V. canescens that emerged in rice containing either parasitoids alone or in combination with neem oil was similar. This indicates minimal or no adverse effect of neem oil on the two parasitoids. It is thus possible to incorporate neem oil in a well-designed pest management program with parasitoids.  相似文献   

17.
The culture supernatant of a strain of Bacillus subtilis isolated from soil samples killed larvae of the mosquito Aedes aegypti. The metabolites produced by B. subtilis were characterized using high performance liquid chromatography (HPLC). Mortality rate was dose-dependent for all larval instars of A. aegypti. Log probit analysis (95% confidence level) revealed an LC50 of 1.73 and an LC90 3.71 μg/ml. Molecular weights/masses of B. subtilis metabolites were confirmed using SDS–PAGE analysis. B. subtilis metabolites were confirmed using HPLC analysis. We demonstrate that secondary metabolites from B. subtilis have larvicidal activity against A. aegypti and may be suitable for the control of this and other mosquito vectors of human disease. The larvae to the metabolites, significant reduction in the activities of acetylcholinesterse, α-carboxylesterase, and acid phosphatases were recorded.  相似文献   

18.
In the present study toxic effects of active molluscicidal component of Areca catechu and Carica papaya was studied on certain enzymes in the nervous tissue of freshwater snail Lymnaea acuminata. In in vivo and in vitro exposure of arecoline (active component of Areca catechu seed) and papain (C. papaya latex and seed) significantly inhibited the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that arecoline and papain caused competitive and uncompetitive inhibition of AChE, respectively, whereas arecoline caused competitive–non-competitive inhibition of ACP/ALP and papain caused non-competitive inhibition of ACP/ALP. Thus the inhibition of AChE, ACP and ALP by arecoline and papain in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of A. catechu and C. papaya, respectively.  相似文献   

19.
桃蚜对噻虫嗪代谢抗性机制研究   总被引：1，自引：0，他引：1  
对桃蚜进行室内噻虫嗪抗性品系筛选,选育至15代后抗性倍数达到75.6倍。对噻虫嗪敏感品系(THI-S)和抗性品系(THI-R)桃蚜的谷胱甘肽S-转移酶(GSTs)、酸性磷酸酯酶(ACP)、碱性磷酸酯酶(ALP)、羧酸酯酶(CarE)、多功能氧化酶(MFO)O-脱甲基活性进行了比较,结果显示:敏感品系(THI-S)和抗性品系(THI-R)的谷胱甘肽S-转移酶比活力分别为3.127 5和3.215 9,差异不显著,桃蚜抗性品系体内酸性磷酸酯酶、碱性磷酸酯酶、羧酸酯酶和多功能氧化酶O-脱甲基活性均显著高于敏感品系,分别达到了1.57、2.10、6.12、2.03倍。表明桃蚜对噻虫嗪抗性的产生与酸性磷酸酯酶、碱性磷酸酯酶、羧酸酯酶和多功能氧化酶O-脱甲基的活性相关。  相似文献   

20.
A study on the compatibility of the entomopathogenic fungus Beauveria bassiana with neem was conducted against sweetpotato whitefly, Bemisia tabaci, on eggplant. Initially, three concentrations of neem (0.25%, 0.5% and 1.0%) were used to investigate the physiological responses of B. bassiana. Thereafter, above three concentrations of neem along with three concentrations of B. bassiana (106, 107 and 108 conidia/ml) were used to investigate combined deterrence index, DI under two application methods (foliar and soil) of B. tabaci. Significant differences were observed among neem concentrations on all variables- germination percentage, vegetative growth, number of conidia, amount of biomass and proteolytic activity of B. bassiana. The reduction percentage of germination, vegetative growth, sporulation, biomass production and proteolytic activity of B. bassiana were as high as 12%, 13%, 35%, 38%, and 34%, respectively, to neem. Significant differences were also observed on deterrence index, DI (adult and oviposition) of B. tabaci. The current study investigated that the highest adult DI (80.15) and oviposition DI (88.25) occurred when 1.0% neem was combined with 108 conidia/ml of B. bassiana. As the results show, neem is compatible with B. bassiana; and soil application of neem along with foliar application of B. bassiana might be useful for the control of B. tabaci.  相似文献   

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